The Seattle Sounders' attempt to acquire Dynamo Kiev attacker Derlis Gonzalez is unlikely to get done before the close of the Major League Soccer summer transfer window on Wednesday, a source with knowledge of the negotiations told ESPN FC.

Seattle has been involved in lengthy talks with Dynamo Kiev throughout the summer and, according to the source, thought that a transfer fee had been agreed upon, only for Dynamo to back out of the deal.

At issue is the fact that the MLS summer transfer window ends on Aug. 9 while the window in Europe ends at the end of this month. For that reason, Dynamo are of the belief that it can get more for Gonzalez on the European market than it can from the Sounders.

The source cautioned that there is a chance that negotiations could resume on Wednesday, but the odds of that happening are now remote.

That Seattle is standing firm in the talks speaks to the very different position it finds itself in as compared to a year ago. Last year, the Sounders were languishing near the bottom of the Western Conference standings, only to have their season revitalized by the midseason arrival of midfielder Nicolas Lodeiro.

The acquisition of the Uruguayan played a huge role in Seattle claiming its first MLS Cup.

This time around, Seattle is in the thick of the playoff race, and the recent acquisitions of defender Kelvin Leerdam and midfielder Victor Rodriguez have given the club confidence that it is well positioned to make another run to the league title.

Midfielder Lamar Neagle's arrival from D.C. United earlier this week isn't believed to be related to the negotiations for Gonzalez.

Jeff Carlisle covers MLS and the U.S. national team for ESPN FC. Follow him on Twitter @JeffreyCarlisle.